Mailer box sizes: common inside dimensions

Where the sizes come from, and choosing one

Mailer boxes have no standard behind them; these are sizes that come up again and again in suppliers’ charts. Vistaprint’s mailer size guide runs from 6 × 4 × 3 in for jewelry and cosmetics to 12 × 10 × 4 in for clothing bundles, with 9.5 × 7.75 × 4 in suggested for coffee bags; Packwire’s guide names 8 × 6 × 4, 10 × 8 × 4 and 12 × 9 × 4 in among common e-commerce sizes; and Uline stocks ready-made white mailers in many sizes, 10 × 8 × 4 in among them. Custom box makers such as Arka and EcoEnclose make mailers to any inside size within their limits, and list sizes as inside dimensions.

Start from the product, not the chart. Measure it with any insert, tissue or padding at its widest, then choose or order the inside size: EcoEnclose suggests adding 0.125 in to the length and width for a snug fit, keeping the depth the same, and then allowing for cushioning. Length and width are the lid; depth is how deep the box is. A box made to the product usually needs less filler than a stock size, and a plain sample shows the fit before you print a run.

The dieline is much bigger than the box

A mailer (a roll end tuck front box) is cut from one flat sheet: the base, the walls, which fold double, the lid, its tuck flap and the dust flaps, so the printed sheet is several times the area of the lid. Panel sizes change with the board’s thickness, about 1.5 mm for E-flute and 3 mm for B-flute, so a dieline drawn for one board won’t fit another. Get the box maker’s dieline for your inside size and board, place the artwork on it at 100%, and don’t redraw it: see setting up a dieline.

Bleed comes with the dieline, usually 0.125 in (3 mm) past every cut edge, but makers set their own. Keep text and logos at least 0.125 in from every crease, more on thicker board, and leave a plain area of at least 4 × 6 in on the panel that will take the shipping label. Kraft board darkens every ink and has no white unless white is printed: see setting up a white ink layer. For plain cartons that ship other boxes, see shipping box sizes.

Questions

What is the most common mailer box size?

There isn’t one standard. Sizes around 8 × 6 × 4, 10 × 8 × 4 and 12 × 9 × 4 in (inside length × width × depth) appear in most suppliers’ charts; smaller 6 × 4 × 3 in boxes suit jewelry and cosmetics, and shallow 12 × 9 × 2 in boxes folded clothing. Size the box to your product and its packing.

Are mailer box sizes inside or outside dimensions?

Inside, at most box makers, including Arka, EcoEnclose and Vistaprint: the length × width × depth of the space the product sits in. The outside is larger by the board on every side, and more where walls fold double, so ask for the outside size too if a shelf or a carrier limits it.

What size is a mailer box dieline?

It depends on the box style, the size and the board, so it comes from the box maker. A mailer is one flat sheet with the lid, walls, tuck flap and dust flaps, several times the area of the lid. Design on the maker’s dieline at 100%: see setting up a dieline.

What size is a mailer box lid in pixels?

At 300 ppi, the lid of a 10 × 8 × 4 in mailer is 3000 × 2400 pixels, a 12 × 9 in lid is 3600 × 2700 and an 8 × 6 in lid 2400 × 1800. Add the maker’s bleed around the whole dieline, and keep logos and type vector.

If the printer sends the file back

• “The artwork doesn’t fit our dieline”
• “There’s no white ink layer”
• “Convert the spot colors to CMYK”
• “Some lines are too thin to print”
• “The text is too close to the edge”